The following United States Patents represent the closest known prior art:
U.S. Pat. No. 1,408,637 PA1 U.S. Pat. No. 2,029,016 PA1 U.S. Pat. No. 2,070,149 PA1 U.S. Pat. No. 2,699,204 PA1 U.S. Pat. No. 3,085,300 PA1 U.S. Pat. No. 3,124,380 PA1 U.S. Pat. No. 3,415,560
In the field of construction of dwellings, commercial buildings, and similar structures, there has been a great increase in recent years in the use of windows and vents which employ sliding panels. These windows and vents usually include a lower channel member having at least one track therein to receive a window or vent panel and permit it to be slidably and horizontally translated. Often these units are preassembled by original equipment manufacturers, and the prefabricated units are then installed with a minimum of labor in wall openings which are dimensioned to receive the units.
Although sliding panel, vent, and window units cannot be blown open by the wind, they are quite suseptible to being opened in an unconventional manner by vandals and thieves. To remedy this situation, there have been devised in the prior art many forms of locks to seal the units and prevent unauthorized entry therethrough. Other lock devices limit the opening afforded by the vent or window to prevent entry therein. In general, these lock devices are an added expense for each window, an expense which is greatly multiplied in a structure having many windows. Also, many of the lock units which require the proper keys for opening are a safety hazard in an emergency, in that they do not permit egress without the use of the proper key. During fires or similar emergencies, the time wasted unlocking a key-locked sliding window may determine the difference between escape and injury or death.
Also known in the prior art are devices which obstruct the track of a channel member to limit the opening of the sliding panel. These devices generally are provided to permit ventilation through a small opening in the sliding panel unit, the opening being insufficient to permit entry therethrough.
The references cited above generally disclose latch mechanisms for windows and sliding panel units, the latch mechanism employing a ball spring-biased into a detent hole. This principle of operation of a latch mechanism is unlike the functioning of the present invention, as are the structures disclosed in the prior art.